Swimming fin

Abstract

A swimming fin includes a blade and a foot pocket, the blade including a relatively long first blade and a short second blade. The second blade underlies a bottom surface of the first blade and has transversely opposite side edge regions longitudinally extending inside transversely opposite side edges of the first blade and an intermediate region extending between the side edge regions and having its front end curved toward the foot pocket. The swimming fin thus formed can strengthen a thrust obtained by down-kicking movement of the swimming fin to thereby facilitate the up-kicking movement of the swimming fin.

What is claimed is: 
     
       1. A swimming fin comprising: a foot pocket having a front end;   a blade extending forward from the front end of said foot pocket; and   said blade including a first blade member and a second blade member shorter than said first blade member and underlying said first blade member,   said second blade member including transversely opposite side edge regions which extend from the front end of said foot pocket forward inside transversely opposite side edges of said first blade member and terminate short of a front end of said first blade member, and an intermediate region which extends between said side edge regions and which has a front end substantially curved toward said foot pocket,   said first and second blade members having rear portions that are held adjacent to one another and forward portions that are separable from one another, so that the second blade member supports the first blade member during a down-kicking movement and does not restrict the first blade member from curving along a longitudinal length during an up-kicking movement.   
     
     
       2. A swimming fin according to claim 1, wherein said foot pocket and said first blade are integral moldings and said second blade is detachably assembled with said moldings. 
     
     
       3. A swimming fin according to claim 1, wherein said second blade member is provided along said side edge regions with arms extending rearward, said arms being removably inserted into longitudinal locking holes formed on transversely opposite outer sides of said foot pocket. 
     
     
       4. A swimming fin according to claim 1, wherein said second blade member, said foot pocket and said first blade member are integral. 
     
     
       5. A swimming fin according to claim 1, wherein said second blade member and said foot pocket are integral. 
     
     
       6. A swimming fin according to claim 1, wherein said second blade member and said first blade member are integral. 
     
     
       7. A swimming fin comprising: a foot pocket having a front end;   a blade extending forward from the front end of said foot pocket; and   said blade including a first blade member and a second blade member shorter than said first blade member and underlying said first blade member,   said second blade member including transversely opposite side edge regions which extend from the front end of said foot pocket forward inside transversely opposite side edges of said first blade member and terminate short of a front end of said first blade member, and an intermediate region which extends between said side edge regions and which has a front end substantially curved toward said foot pocket,   said foot pocket and said first blade being integral moldings and said second blade being detachably assembled with said moldings.   
     
     
       8. A swimming fin comprising: a foot pocket having a front end;   a blade extending forward from the front end of said foot pocket; and   said blade including a first blade member and a second blade member shorter than said first blade member and underlying said first blade member,   said second blade member including transversely opposite side edge regions which extend from the front end of said foot pocket forward inside transversely opposite side edges of said first blade member and terminate short of a front end of said first blade member, and an intermediate region which extends between said side edge regions and which has a front end substantially curved toward said foot pocket,   said second blade being provided along said side edge regions with arms that extend rearward and are removably inserted into longitudinal locking holes formed on transversely opposite outer sides of said foot pocket.